Channel Bot

Channels — Telegram, Slack, Mattermost

Read docs/channels.md. Code: app/services/channels/ — a thick service with per-platform adapters plus a router that funnels inbound messages into the same agent pipeline as the web chat.

Bots live in the DB (channel_bots), with per-user identity (channel_identity) and per-thread session (channel_session).

Tokens go through the vault

Bot tokens are sealed with app/core/vault.py, bound to the organization. CHANNEL_ENCRYPTION_KEY and the deployment-wide Fernet key are gone, removed before the chain was squashed into 0001_baseline. channel_bots.secret_key_version exists because the token is now an envelope and a staged master-key rotation has to know which key sealed it. See the vault-secrets skill.

The mention invariants

These are the ones worth testing and the ones easiest to break:

• A bot serves exactly one agent - uq_exposure_bot, migration 0018. So answer_default takes the single active binding without asking what a second row would have meant, and @slug is an alias for that agent rather than a router between several. Binding a second agent is refused by the service and by the database.
• @slug resolves only inside the bot's organization. A slug from another org is not found, not borrowed.
• A mention runs as the sender, never as the bot. The bot's own identity would carry whatever permissions it was registered with, which is how a channel becomes a privilege-escalation path.
• An unlinked identity is refused, not run with no role. "No role" is not a safe default; it is an unauthenticated run.

tests/test_channel_mentions.py and tests/test_channel_bot_org_scope.py pin these.

CLI

uv run agenticos cmd channel-add-bot \
    --platform telegram --name "Support" --token <token> --mode jwt_linked
uv run agenticos cmd channel-list-bots [--platform telegram]
uv run agenticos cmd channel-test-message --bot-id <uuid> --chat-id <chat> --text ping
uv run agenticos cmd channel-webhook-register --bot-id <uuid>
uv run agenticos cmd channel-webhook-delete --bot-id <uuid>   # back to polling

There is no cmd channel group — the commands are flat, hyphenated names.

Access modes: open, whitelist, jwt_linked, group_only. jwt_linked refuses an unlinked chat account everywhere on its own; require_link is the switch that makes the other modes refuse in a channel too (#639).

Webhook vs polling

• Polling (dev) — the adapter long-polls; no public URL needed.
• Webhook (prod) — the platform POSTs to a route under api/routes/v1/. Verify the signature or secret before processing anything (HMAC for Telegram, signing secret for Slack).

Adding an adapter

1. Implement services/channels/<platform>.py against base.py: parse inbound into the normalized message, send outbound. Anything per bot the connection needs before it opens - a server address, an app token - is registered in prepare_connection, the base hook the supervisor calls on every adapter; do not add a differently named method for it.
2. Wire it into router.py so inbound reaches the agent and replies stream back. Do not fork the agent pipeline — one runner behind every surface is the whole design.
3. Add a signature-verified webhook route and/or a polling entrypoint. A polling entrypoint runs its session under supervise_stream from base.py — the one reconnect loop — and raises ChannelNotConfigured for anything a retry cannot fix (a missing token or URL, a token the platform rejects); do not hand-roll a while True with its own sleep.
4. Reuse the existing conversation/session model.
5. Respect the per-group/per-thread concurrency controls already in the adapters.

Where charts come from

Two halves, and the split is the point. The charts capability (app/agents/capabilities/charts/) owns the spec: create_chart returns a ChartSpec, which the web chat renders with Recharts and a replay draws again. A chat platform can render neither, so services/channels/chart_png.py owns the channel raster: mentions.drawn_chart takes the turn's last chart call and render_chart_png rasterises it to a PNG the adapter attaches. RENDERERS there is one entry per ChartType, held equal to the capability's list by tests/test_channel_charts.py — a new type is added in both places or fails there. There is no chart_render.py; the file is chart_png.py.

Coverage

app/services/channels/mentions.py is in the gated platform layer at 100%. The adapters are template-inherited and are not. See the backend-tests skill.